scispace - formally typeset
Search or ask a question
RepositoryDOI

EuCAPT White Paper: Opportunities and Challenges for Theoretical Astroparticle Physics in the Next Decade

R. Alves Batista, Amin, G. Barenboim, Nicola Bartolo, Daniel Baumann, A. Bauswein, Emilio Bellini, D. Benisty, Gianfranco Bertone, P. Blasi, C.G. Böhmer, Ž Bošnjak, T. Bringmann, Clare Burrage, M. Bustamante, J. Calderón Bustillo, C.T. Byrnes, F. Calore, R. Catena, D.G. Cerdeño, S.S. Cerri, Marco Chianese, Katy Clough, Alex Cole, P. Coloma, Adam Coogan, L. Covi, D. Cutting, A.C. Davis, C. De Rham, A. Di Matteo, G. Domènech, M. Drewes, T. Dietrich, T.D.P. Edwards, I. Esteban, R. Erdem, C. Evoli, Matteo Fasiello, S.M. Feeney, R.Z. Ferreira, A. Fialkov, N. Fornengo, S. Gabici, T. Galatyuk, Daniele Gaggero, D. Grasso, C. Guépin, J. Harz, M. Herrero-Valea, T. Hinderer, N.B. Hogg, D.C. Hooper, D. Iocco, J. Isern, Konstantin Karchev, Bradley J. Kavanagh, M. Korsmeier, K. Kotera, Kazuya Koyama, B. Krishnan, Julien Lesgourgues, J. Levi Said, Lucas Lombriser, C.S. Lorenz, S. Manconi, M. Mapelli, A. Marcowith, S.B. Markoff, D.J. Marsh, M. Martinelli, C.J.A.P. Martinsolami, P. Millington, P. Moesta, K. Nippel, V. Niro, E. O'Connor, F. Oikonomou, C.F. Paganini, G. Pagliaroli, Paolo Pani, C. Pfrommer, Silvia Pascoli, L. Pinol, L. Pizzuti, R.A. Porto, A. Pound, F. Quevedo, G.G. Raffelt, Alvise Raccanelli, E. Ramirez-Ruiz, M. Raveri, S. Renaux-Petel, Angelo Ricciardone, A. Rida Khalifeh, Antonio Riotto, R. Roiban, J. Rubio, M. Sahlén, Nashwan Sabti, L. Sagunski, N. Šarčević, K. Schmitz, Pedro Schwaller, T. Schwetz, A. Sedrakian, E. Sellentin, A. Serenelli, P.D. Serpico, E.I. Sfakianakis, S. Shalgar, A. Silvestri, I. Tamborra, Konstantinos Tanidis, D. Teresi, A.A. Tokareva, L. Tolos, S. Trojanowski, R. Trotta, C. Uhlemann, F.R. Urban, Filippo Vernizzi, A. van Vliet, F.L. Villante, A. Vincent, J. Vink, E. Vitagliano, Christophe Weniger, A. Wickenbrock, W. Winter, S. Zell, M. Zeng 
TL;DR: The European Consortium for Astroparticle Theory (EuCAPT) white paper as mentioned in this paper explores upcoming theoretical opportunities and challenges for our field of research with particular emphasis on the possible synergies among different subfields, and the prospects for solving the most fundamental open questions with multi-messenger observations.
Abstract: Astroparticle physics is undergoing a profound transformation, due to a series of extraordinary new results, such as the discovery of high-energy cosmic neutrinos with IceCube, the direct detection of gravitational waves with LIGO and Virgo, and many others. This white paper is the result of a collaborative effort that involved hundreds of theoretical astroparticle physicists and cosmologists, under the coordination of the European Consortium for Astroparticle Theory (EuCAPT). Addressed to the whole astroparticle physics community, it explores upcoming theoretical opportunities and challenges for our field of research, with particular emphasis on the possible synergies among different subfields, and the prospects for solving the most fundamental open questions with multi-messenger observations.
Citations
More filters
Journal Article
TL;DR: The first direct detection of gravitational waves and the first observation of a binary black hole merger were reported in this paper, with a false alarm rate estimated to be less than 1 event per 203,000 years, equivalent to a significance greater than 5.1σ.
Abstract: On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10(-21). It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203,000 years, equivalent to a significance greater than 5.1σ. The source lies at a luminosity distance of 410(-180)(+160) Mpc corresponding to a redshift z=0.09(-0.04)(+0.03). In the source frame, the initial black hole masses are 36(-4)(+5)M⊙ and 29(-4)(+4)M⊙, and the final black hole mass is 62(-4)(+4)M⊙, with 3.0(-0.5)(+0.5)M⊙c(2) radiated in gravitational waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.

4,375 citations

Journal Article
TL;DR: The North American Nanohertz Observatory for Gravitational Waves (NANOW) is a collaboration of researchers who are actively engaged in using North American radio telescopes to detect and study gravitational waves (GWs) via pulsar timing.
Abstract: The North American Nanohertz Observatory for Gravitational Waves is a collaboration of researchers who are actively engaged in using North American radio telescopes to detect and study gravitational waves (GWs) via pulsar timing. To achieve this goal, we regularly observe millisecond pulsars with the Arecibo and Green Bank telescopes and develop and implement new instrumentation and algorithms for searching for and observing pulsars, calculating arrival times, understanding and correcting for propagation delays and sources of noise in our data and detecting and characterizing a variety of GW sources. We collaborate on these activities with colleagues in the International Pulsar Timing Array. We also educate students of all levels and the public about the detection and study of GWs via pulsar timing.

218 citations

01 Jun 2012
TL;DR: In this article, it was shown that in a class of well-motivated single-field models, inflation is followed by self resonance, leading to copious oscillon generation and a lengthy period of oscillon domination.
Abstract: Oscillons are massive, long-lived, localized excitations of a scalar field. We show that in a class of well-motivated single-field models, inflation is followed by self resonance, leading to copious oscillon generation and a lengthy period of oscillon domination. These models are characterized by an inflaton potential which has a quadratic minimum and is shallower than quadratic away from the minimum. This set includes both string monodromy models and a class of supergravity inspired scenarios and is in good agreement with the current central values of the concordance cosmology parameters. We assume that the inflaton is weakly coupled to other fields so as not to quickly drain energy from the oscillons or prevent them from forming. An oscillon-dominated universe has a greatly enhanced primordial power spectrum on very small scales relative to that seen with a quadratic potential, possibly leading to novel gravitational effects in the early Universe.

116 citations

01 Jun 2014
TL;DR: In this paper, the authors present extensive radio and millimeter observations of the unusually bright GRB-130427A at z = 0.340, spanning 0.67-12 days after the burst.
Abstract: We present extensive radio and millimeter observations of the unusually bright GRB 130427A at z = 0.340, spanning 0.67-12 days after the burst. We combine these data with detailed multi-band UV, optical, NIR, and Swift X-ray observations and find that the broadband afterglow emission is composed of distinct reverse shock and forward shock contributions. The reverse shock emission dominates in the radio/millimeter and at 0.1 days in the UV/optical/NIR, while the forward shock emission dominates in the X-rays and at 0.1 days in the UV/optical/NIR. We further find that the optical and X-ray data require a wind circumburst environment, pointing to a massive star progenitor. Using the combined forward and reverse shock emission, we find that the parameters of the burst include an isotropic kinetic energy of E K, iso 2 × 1053 erg, a mass loss rate of M ☉ yr–1 (for a wind velocity of 1000 km s–1), and a Lorentz factor at the deceleration time of Γ(200 s) 130. Due to the low density and large isotropic energy, the absence of a jet break to 15 days places only a weak constraint on the opening angle, θj 2.°5, and therefore a total energy of E γ + EK 1.2 × 1051 erg, similar to other gamma-ray bursts (GRBs). The reverse shock emission is detectable in this burst due to the low circumburst density, which leads to a slow cooling shock. We speculate that this property is required for the detectability of reverse shocks in radio and millimeter bands. Following on GRB 130427A as a benchmark event, observations of future GRBs with the exquisite sensitivity of the Very Large Array and ALMA, coupled with detailed modeling of the reverse and forward shock contributions, will test this hypothesis.

88 citations

Posted Content
TL;DR: The main criticism of my piece in this article seems to be that my calculations rely on testing a point null hypothesis, i.e. the hypothesis that the true effect size is zero.
Abstract: The main criticism of my piece in ref (2) seems to be that my calculations rely on testing a point null hypothesis, i.e. the hypothesis that the true effect size is zero. He objects to my contention that the true effect size can be zero, "just give the same pill to both groups", on the grounds that two pills can't be exactly identical. He then says "I understand that this criticism may come across as frivolous semantic pedantry of no practical consequence: of course that the author meant to say 'pills with the same contents' as everybody would have understood". Yes, that is precisely how it comes across to me. I shall try to explain in more detail why I think that this criticism has little substance.

84 citations

References
More filters
Proceedings Article
01 Jan 2014
TL;DR: A stochastic variational inference and learning algorithm that scales to large datasets and, under some mild differentiability conditions, even works in the intractable case is introduced.
Abstract: How can we perform efficient inference and learning in directed probabilistic models, in the presence of continuous latent variables with intractable posterior distributions, and large datasets? We introduce a stochastic variational inference and learning algorithm that scales to large datasets and, under some mild differentiability conditions, even works in the intractable case. Our contributions is two-fold. First, we show that a reparameterization of the variational lower bound yields a lower bound estimator that can be straightforwardly optimized using standard stochastic gradient methods. Second, we show that for i.i.d. datasets with continuous latent variables per datapoint, posterior inference can be made especially efficient by fitting an approximate inference model (also called a recognition model) to the intractable posterior using the proposed lower bound estimator. Theoretical advantages are reflected in experimental results.

20,769 citations


"EuCAPT White Paper: Opportunities a..." refers methods in this paper

  • ...[1262] D....

    [...]

  • ...The ELBO is most easily optimized with respect to the parameters φ by using stochastic gradient descent and the reparametrization trick [1262, 1263] to differentiate the expectation in Eq....

    [...]

Journal ArticleDOI
TL;DR: In this paper, the mass density, Omega_M, and cosmological-constant energy density of the universe were measured using the analysis of 42 Type Ia supernovae discovered by the Supernova Cosmology project.
Abstract: We report measurements of the mass density, Omega_M, and cosmological-constant energy density, Omega_Lambda, of the universe based on the analysis of 42 Type Ia supernovae discovered by the Supernova Cosmology Project. The magnitude-redshift data for these SNe, at redshifts between 0.18 and 0.83, are fit jointly with a set of SNe from the Calan/Tololo Supernova Survey, at redshifts below 0.1, to yield values for the cosmological parameters. All SN peak magnitudes are standardized using a SN Ia lightcurve width-luminosity relation. The measurement yields a joint probability distribution of the cosmological parameters that is approximated by the relation 0.8 Omega_M - 0.6 Omega_Lambda ~= -0.2 +/- 0.1 in the region of interest (Omega_M <~ 1.5). For a flat (Omega_M + Omega_Lambda = 1) cosmology we find Omega_M = 0.28{+0.09,-0.08} (1 sigma statistical) {+0.05,-0.04} (identified systematics). The data are strongly inconsistent with a Lambda = 0 flat cosmology, the simplest inflationary universe model. An open, Lambda = 0 cosmology also does not fit the data well: the data indicate that the cosmological constant is non-zero and positive, with a confidence of P(Lambda > 0) = 99%, including the identified systematic uncertainties. The best-fit age of the universe relative to the Hubble time is t_0 = 14.9{+1.4,-1.1} (0.63/h) Gyr for a flat cosmology. The size of our sample allows us to perform a variety of statistical tests to check for possible systematic errors and biases. We find no significant differences in either the host reddening distribution or Malmquist bias between the low-redshift Calan/Tololo sample and our high-redshift sample. The conclusions are robust whether or not a width-luminosity relation is used to standardize the SN peak magnitudes.

16,838 citations

Journal ArticleDOI
B. P. Abbott1, Richard J. Abbott1, T. D. Abbott2, Matthew Abernathy1  +1008 moreInstitutions (96)
TL;DR: This is the first direct detection of gravitational waves and the first observation of a binary black hole merger, and these observations demonstrate the existence of binary stellar-mass black hole systems.
Abstract: On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of $1.0 \times 10^{-21}$. It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203 000 years, equivalent to a significance greater than 5.1 {\sigma}. The source lies at a luminosity distance of $410^{+160}_{-180}$ Mpc corresponding to a redshift $z = 0.09^{+0.03}_{-0.04}$. In the source frame, the initial black hole masses are $36^{+5}_{-4} M_\odot$ and $29^{+4}_{-4} M_\odot$, and the final black hole mass is $62^{+4}_{-4} M_\odot$, with $3.0^{+0.5}_{-0.5} M_\odot c^2$ radiated in gravitational waves. All uncertainties define 90% credible intervals.These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.

9,596 citations


"EuCAPT White Paper: Opportunities a..." refers background in this paper

  • ...7 Black holes The first direct detection of gravitational waves [943] opened new perspectives for the study of stellar mass BHs, their mass spectrum and spin distribution....

    [...]

  • ...[943] LIGO Scientific, Virgo Collaboration, B....

    [...]

Journal ArticleDOI
TL;DR: The second Gaia data release, Gaia DR2 as mentioned in this paper, is a major advance with respect to Gaia DR1 in terms of completeness, performance, and richness of the data products.
Abstract: Context. We present the second Gaia data release, Gaia DR2, consisting of astrometry, photometry, radial velocities, and information on astrophysical parameters and variability, for sources brighter than magnitude 21. In addition epoch astrometry and photometry are provided for a modest sample of minor planets in the solar system. Aims: A summary of the contents of Gaia DR2 is presented, accompanied by a discussion on the differences with respect to Gaia DR1 and an overview of the main limitations which are still present in the survey. Recommendations are made on the responsible use of Gaia DR2 results. Methods: The raw data collected with the Gaia instruments during the first 22 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into this second data release, which represents a major advance with respect to Gaia DR1 in terms of completeness, performance, and richness of the data products. Results: Gaia DR2 contains celestial positions and the apparent brightness in G for approximately 1.7 billion sources. For 1.3 billion of those sources, parallaxes and proper motions are in addition available. The sample of sources for which variability information is provided is expanded to 0.5 million stars. This data release contains four new elements: broad-band colour information in the form of the apparent brightness in the GBP (330-680 nm) and GRP (630-1050 nm) bands is available for 1.4 billion sources; median radial velocities for some 7 million sources are presented; for between 77 and 161 million sources estimates are provided of the stellar effective temperature, extinction, reddening, and radius and luminosity; and for a pre-selected list of 14 000 minor planets in the solar system epoch astrometry and photometry are presented. Finally, Gaia DR2 also represents a new materialisation of the celestial reference frame in the optical, the Gaia-CRF2, which is the first optical reference frame based solely on extragalactic sources. There are notable changes in the photometric system and the catalogue source list with respect to Gaia DR1, and we stress the need to consider the two data releases as independent. Conclusions: Gaia DR2 represents a major achievement for the Gaia mission, delivering on the long standing promise to provide parallaxes and proper motions for over 1 billion stars, and representing a first step in the availability of complementary radial velocity and source astrophysical information for a sample of stars in the Gaia survey which covers a very substantial fraction of the volume of our galaxy.

8,308 citations


Additional excerpts

  • ...[1338] Gaia Collaboration, A....

    [...]

Journal ArticleDOI
B. P. Abbott1, Richard J. Abbott1, T. D. Abbott2, Fausto Acernese3  +1131 moreInstitutions (123)
TL;DR: The association of GRB 170817A, detected by Fermi-GBM 1.7 s after the coalescence, corroborates the hypothesis of a neutron star merger and provides the first direct evidence of a link between these mergers and short γ-ray bursts.
Abstract: On August 17, 2017 at 12∶41:04 UTC the Advanced LIGO and Advanced Virgo gravitational-wave detectors made their first observation of a binary neutron star inspiral. The signal, GW170817, was detected with a combined signal-to-noise ratio of 32.4 and a false-alarm-rate estimate of less than one per 8.0×10^{4} years. We infer the component masses of the binary to be between 0.86 and 2.26 M_{⊙}, in agreement with masses of known neutron stars. Restricting the component spins to the range inferred in binary neutron stars, we find the component masses to be in the range 1.17-1.60 M_{⊙}, with the total mass of the system 2.74_{-0.01}^{+0.04}M_{⊙}. The source was localized within a sky region of 28 deg^{2} (90% probability) and had a luminosity distance of 40_{-14}^{+8} Mpc, the closest and most precisely localized gravitational-wave signal yet. The association with the γ-ray burst GRB 170817A, detected by Fermi-GBM 1.7 s after the coalescence, corroborates the hypothesis of a neutron star merger and provides the first direct evidence of a link between these mergers and short γ-ray bursts. Subsequent identification of transient counterparts across the electromagnetic spectrum in the same location further supports the interpretation of this event as a neutron star merger. This unprecedented joint gravitational and electromagnetic observation provides insight into astrophysics, dense matter, gravitation, and cosmology.

7,327 citations


"EuCAPT White Paper: Opportunities a..." refers background in this paper

  • ...Moreover, gravitational waves from binary NS mergers [929] are a new venue for extracting information, not only on the EoS but also on the transport properties....

    [...]

  • ...[929] LIGO Scientific, Virgo Collaboration, B....

    [...]